Hi vibhash,
Sorry to hear how things went with your GMAT. The good news is that your verbal was pretty much in line with your practice test scores (despite low SC). However, your quant took a pretty major hit. If you can improve your quant score to 49+ and improve your SC skills (and thus your verbal score), you should be able to hit your 700 score goal. I’m happy to provide some advice on how to improve those skills. Let’s start with quant.
I realize that you are hoping to craft a master plan based on your ESR; however, you need to make sure that you avoid falling into the trap of focusing on micro-details based on your ESR, and thus misdiagnosing your weaknesses. Since your ESR is based on only 31 quant questions (a very small sample size), it may not give you a complete picture of what to focus on going forward. For example, does your scoring 87% in RATES/RATIO/PERCENT mean that you are devoid of weakness in those topics? Not necessarily. Perhaps you were given many lower-level questions or had some lucky guesses on those topics. Furthermore, there is no way to know HOW MANY questions you were given from those topics, right?
A few things do seem clear. For one, your ESR seems to indicate that you are not strong in COUNTING/SETS/SERIES, EQUALITIES/INEQUALITIES/ALGEBRA, and VALUE/ORDER/FACTORS. So, by becoming super-strong in those areas, you likely would score a few points higher in quant.
With all that said, the safest path forward to improve your quant score is to go through GMAT quant carefully to find your exact weaknesses, fill gaps in your knowledge, and strengthen your skills. The overall process will be to learn all about how to answer question types with which you currently aren't very comfortable and do dozens of practice questions category by category, basically driving up your score point by point. For example, if you find that you are not strong in answering Number Properties questions, then carefully review the conceptual underpinnings of how to answer Number Properties questions and practice by answering 50 or more questions just from Number Properties: LCM, GCF, units digit patterns, divisibility, remainders, etc. When you are working on learning to answer questions of a particular type, start off taking your time, and then seek to speed up as you get more comfortable answering questions of that type. As you do such practice, do a thorough analysis of each question that you don't get right. If you got a remainder question wrong, ask yourself why. Did you make a careless mistake? Did you not properly apply the remainder formula? Was there a concept you did not understand in the question? By carefully analyzing your mistakes, you will be able to efficiently fix your weaknesses and in turn improve your GMAT quant skills. Number Properties is just one example; follow this process for all quant topics.
Regarding Sentence Correction, there are three aspects to getting correct answers: what you know, such as grammar rules, what you see, such as violations of grammar rules and the logic of sentence structure, and what you do, such as carefully considering each answer choice in the context of the non-underlined portion of the sentence. To drive up your Sentence Correction score, you likely will have to work on all three of those aspects.
Regarding what you know, first and foremost, you MUST know your grammar rules. Let's be clear, though: GMAT Sentence Correction is not really a test of knowledge of grammar rules. The reason for learning the grammar rules is so that you can determine what sentences convey and whether sentences are well-constructed. In fact, in many cases, incorrect answers to Sentence Correction questions are grammatically flawless. Thus, often your task is to use your knowledge of grammar rules to determine which answer choice creates the most logical sentence meaning and structure.
This determination of whether sentences are well-constructed and logical is the second aspect of finding correct answers to Sentence Correction questions, what you see. To develop this skill, you probably have to slow way down. You won't develop this skill by spending less than two minutes per question. For a while, anyway, you have to spend time with each question, maybe even ten or fifteen minutes on one question sometimes, analyzing every answer choice until you see the details that you have to see in order to choose the correct answer. As you go through the answer choices, consider the meaning conveyed by each version of the sentence. Does the meaning make sense? Even if you can tell what the version is SUPPOSED to convey, does the version really convey that meaning? Is there a verb to go with the subject? Do all pronouns clearly refer to nouns? By slowing way down and looking for these details, you learn to see what you have to see in order to clearly understand which answer to a Sentence Correction question is correct.
There is only one correct answer to any Sentence Correction question, there are clear reasons why that choice is correct and the others are not, and none of those reasons are that the correct version simply "sounds right." In fact, the correct version often sounds a little off at first. That correct answers may sound a little off is not surprising. If the correct answers were always the ones that sounded right, then most people most of the time would get Sentence Correction questions correct, without really knowing why the wrong answers were wrong and the correct answers were correct. So, you have to go beyond choosing what "sounds right" and learn to clearly see the logical reasons why one choice is better than all of the others.
As for the third aspect of getting Sentence Correction questions correct, what you do, the main thing you have to do is be very careful. You have to make sure that you are truly considering the structures of sentences and the meanings conveyed rather than allowing yourself to be tricked into choosing trap answers that sound right but don't convey logical meanings. You also have to make sure that you put some real energy into finding the correct answers. Finding the correct answer to a Sentence Correction question may take bouncing from choice to choice until you start to see the differences that make all choices wrong except for one. Often, when you first look at the choices, only one or two seem obviously incorrect. Getting the right answers takes a certain work ethic. You have to take the time to see the differences between answers and to figure out the precise reasons that one choice is correct.
To improve what you do when you answer Sentence Correction questions, seek to become aware of how you are going about answering them. Are you being careful and looking for logic and details, or are you quickly eliminating choices that sound a little off, and then choosing the best of the rest? If you choose an incorrect answer, consider what you did to arrive at that answer and what you could do differently to arrive at correct answers more consistently. Furthermore, see how many questions you can get correct in a row as you practice. If you break your streak by missing one, consider what you could do differently to extend your streak.
Feel free to reach out with further questions.